This invention relates to remote metering systems. More particularly, it involves a system for receiving data from a plurality of metering devices, analyzing it, and transmitting data associated with such metering devices to remote locations.
The primary use of this invention is in the area of energy management. In such applications, sensors or meters provide an output indicative of the consumption of various energy sources such as electricity, steam, water, gas, etc. Since utility bills are based not only on the total consumption but also on the peak demand within a particular time period, by continually monitoring the energy consumption, non-critical loads can be shed during times of high energy usage to minimize the peak demand and thus utility costs. Examples of commercially available systems include the NUMA-LOGIC Programmable Energy Controller manufactured by Westinghouse Electric Corporation and Veeder-Root's Modular Industrial Data Acquisition System. However, these and other prior art systems have been limited in their abilities to efficiently manage and transmit the data received from the meters. For example, the Veeder-Root system requires a monitor/transmitter for each metering device and merely transmits the same information to a remote display. The Westinghouse system requires plug-in input/output modules for the meters and merely turns selected loads on or off. There is no provision for any data transmission to remote displays. Another similar system is disclosed in U.S. Pat. No. 4,090,088 to McMahon et al, issued May 16, 1978.
There are many other applications for remote metering devices. One such other application is piece counting in a production line environment. A meter provides a signal indicative of a particular unit being completed. This signal is sent to a remote location where the number of units completed is accumulated so that production output can be monitored.
The present invention provides a more flexible and economically efficient improvement over known remote metering systems. It provides the ability to combine data from selected metering devices for transmission to at least one remote data receiving device. For example, all of the electric meters in a plant can be summed together and sent to a display in the manager's office. Moreover, different data transmissions are provided sequentially in serial format and the various remote devices are adapted to receive selected data transmissions, as desired. Consequently, a remote display can receive many different data transmissions without the need for separate wiring connections to each meter.